The effects of fishing and fish traps on fish assemblages within Virgin Islands National Park and Buck Island Reef National Monument

Beets, Jim

The results of research from this project, combined with available historical information, yield an alarming view of the degraded condition offish assemblages in Virgin Islands National Park and Buck Island Reef National Monument. Commercial and personal-use (or sustenance) fishing (primarily trap fishing) is responsible for declining resources. Coastal development and natural disturbance (primarily hurricanes) contribute to ecosystem changes, such as shifts to algal dominated reefs and low-diversity inshore habitats. Several results show the impact of trap fishing within park waters. Comparison of fish trap data from one location (the Lameshur Bays, St. John) collected in 1982-3 and 1993-4 show that the preferred fishery species (primarily the predatory groupers and snappers) have declined in relative abundance, whereas, the less preferred species (primarily the herbivorous parrotfishes and surgeonfishes) have increased. This has profound ecological consequences to entire reef communities as well as fish assemblages. Coral reef condition is greatly affected by the fishes which use the coral reef for shelter and food. Shifts in the abundances of predatory and herbivorous fishes may result in algal overgrowth on reefs and may affect the abundance of other organisms. Many fish species have declined in average size. A trapping experiment at this location showed that fishing a small number of traps (8) over a period of six months negatively affected the abundance of fishes on a reef. Virgin Islands National Park and Buck Island ReefNational Monument provide little protection to fisheries resources. Fisheries regulations are rarely enforced and most traps observed during underwater surveys conducted in Virgin Islands National Park were illegal based on defined criteria. The greatest problem is the lack of degradable panels, without which traps continue to kill when lost or abandoned. Another destructive trap problem is small mesh size, which does not allow small fish to escape and grow to reproductive size. Few differences were observed in catch rates, fish species composition and abundances, and fish sizes between park waters and surrounding waters. In fact, catch rates within Virgin Islands National Park were lower than those obtained in a previous study north of St. Thomas. Underwater surveys conducted in Virgin Islands National Park and Buck Island Reef National Monument documented a large number of active fish traps. Three intensive surveys were conducted around St. John, with as many as 58 fish traps with buoys (an unknown number were unbuoyed) observed within Virgin Islands National Park boundaries during one survey. Over 20 fishermen set traps within Virgin Islands National Park and harvest an estimated 12,000 fishes per year from park waters (probably a large underestimate). Approximately 6 trap fishermen operate around Buck Island, St. Croix and set over 40 traps within park boundaries. Commercial fishing is illegal in park waters, but it obviously is occurring.

The effects of fishing and fish traps on fish assemblages within Virgin Islands National Park and Buck Island Reef National Monument

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